1. Field of the Invention
The present invention is generally related to network infrastructure devices supporting network access to remotely stored data and, in particular, an infrastructure gateway network appliance implementing file storage access policies against client network file access transactions to flexibly determine and control secure network file access transactions initiated against remote network file storage resources.
2. Description of the Related Art
The use and concomitant evolution of network information systems continues to grow at a substantial pace. Organizations of all sizes, though particularly larger, typically corporate environments, are producing and redeploying information at increasing rates as part of the fundamental business processes implemented by those organizations. In a typical scenario, such as encountered in many parts of the financial, scientific, and manufacturing industries, various files detailing transactions are routinely created and centrally stored for individual and aggregate processing. This same information is then routinely redeployed for interactive use by captive customer service representatives, select component and service suppliers, and often for limited end user access through typically Web-based network interfaces. File stores that measure in the range of tens to hundreds of terabytes are commonplace.
As an initial matter, the growth in the volume and need for wide accessibility of information is reflected in increasing interest in network attached storage (NAS) and storage area networks (SANs). These technologies support a network-based storage architecture that enables a fundamental independence between the various client, application and network server systems used to access and process stored data and the expansion, configuration, and management of large data storage systems. Other fundamental capabilities provided by network-based storage architectures include the ability to geographically distribute and, further, replicate the data stores, which permit remote data backup and hot fail-over of typically business and real-time transaction processing storage systems.
While the many enabling capabilities of network-based storage architectures are of substantial value, issues of authentication, access control, and security over the stored data remain. Indeed, the ubiquitous data accessibility inherently afforded by network-based storage architectures is commonly viewed as greatly exacerbating the problems of assuring authentication, access, and security control. The network transport costs associated with delivering and accessing remotely stored data is also recognized as a significant problem.
Conventional direct attached storage (DAS) architectures, involving application and network servers with dedicated, locally attached storage arrays, have evolved various forms of authentication, access and security controls to protect stored data. These controls run from basic operating system password authentication and access permission attributes to smart cards and physical access barriers. The successive layering of these controls can be used to progressively harden the underlying direct-attached storage.
While some of the conventional protection controls remain generally applicable to network-based storage architectures, many are, as a practical matter, ineffective. In network-based storage architectures, the storage accessing application servers are typically remotely distributed, which generally precludes any assurance that authorization, access, and security controls are not intentionally or inadvertently circumvented. Even fewer assurances exist for the remotely distributed client computer systems permitted access to the network shared with the network storage.
The vulnerabilities of conventional network-based storage architectures are appreciated and, as a result, have significantly limited the rapid adoption of NAS and SAN technologies. Other technologies, such as virtual private networking (VPN), are useful in overcoming certain of the limitations of network-based storage architectures. VPNs support a robust encryption of data in transport between the endpoint systems within a VPN session. Thus, conventional VPNs can be used to provide point-to-point security over data transported between various client computer systems, application servers, and the network storage systems.
VPN and similar technologies, however, fail to support any meaningful access controls or assure the continuing security of data once delivered to a VPN endpoint system. The underlying protocols were simply not designed to provide or enforce storage-type access controls. VPN data, while encrypted and secure during transport, is delivered to a VPN host endpoint subject only to the access controls implemented by the host. The data is also delivered unencrypted and thus again subject only to the security controls provided by the host.
Other technologies can be potentially employed to layer general access and security controls onto the secure transport capabilities of VPN and similar technologies. Various standard protocols, such as the Kerberos protocol (web.mit.edu/kerberos/www/) and the Lightweight Directory Access Protocol (LDAP; www.openldap.org) can be utilized to differing degrees to provide secure authentication, directory services, and access controls. Encrypting file systems can be utilized to secure file data as stored. Together, these technologies can provide for a well-hardened storage of data within a network-based storage architecture. Considering the requisite separate administration of these technology layers over disparate client computer systems and application servers, however, makes assuring that data is properly subject to rigorously enforced authentication, access and security controls practically impossible.
Consequently, there remains a fundamental, unsolved tension between ensuring only properly secure access to network-based stored data and enabling appropriate widespread access to the data in fulfillment of business process requirements.